Liquid-spraying device



K.v LUDWIG i LIQUI-DSPRAYING DEVICE Original Filed Aug. 31, 1927 -'iNo/v. 1s, 1930.

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, L @cof Patented Nov. 18, 1930l `um'ri-:D STATES PAT-ENT OFFICE KARL LUDWIG, F HAMBURG, GERMANY, ASSIGNOR T0 HUNDERTFEUER GESELL- SCHAFT FR' MODERNE BAUTENTECHNIK MIT BESCHRNKTER HAFTUN G, OF HAM-l BURG, GERMANY LIQUID-SPRAYING DEVICE `thiginal application led August 31, 1927, Serial No. 216,637, and in Germany August 31, 1926. Divided and this application led October 31, 1928. Serial No. 316,305. 1

This application is a division of my earlier application, Serial No. 216,637 iled in the U. S. Patent Oice, Aug. 31, 1927.

" The invention relates to a device adaptedto 5 spray liquids bymeans of al current of air and project theni to the position of use. It is also adapted to extend the possibilities of application of dust suction devices.

Spraying devices are known which spray liquids with highly compressedair by the action of nozzles or bymeans of impellers driven by special machines, such as .electric motors, for example, paint spraying pistols or centrifugal cement applying devices. Y According to the invention, a mechanically operating atomizing device kis mounted in. front of the discharge opening and operated by a rotor driven by the current of air. The atomizing device may be a stepped centrifugal cone to which the liquid to be sprayed is supplied through a needle valve.' The liquid mist formed is blown in a direction substantially axial by the discharge of the air current u through a suitable nozzle.

The atomizing device may be so constructed that as reat as possible a breaking up of the liquid 1s produced with the smallest expenditure of work. For this purpose a censo trifugal cone preferably stepped is employed 3.5. Preferably the base of the cone slopes bacln. from its outer edge to the edge of the recess.

to which is secured a rear annular wall spaced i caslng 13 1s arranged with the same axis a from the cone by spacing bolts. The centrifugal cone is also provided with a recess in its rear surface to which the liquid is supplied.

The annular wall is preferably arranged parallel to the sloping base for part of its distance between inner and outer diameters and has its front part bent forward somewhat.

Fig. 1 isan elevation partly in longitudinal section showing the preferred form of construction for high pressure operation.

. Fig. 2. is part 'view in section showing a modification in the construction .of Fig. 1,

, suitable for low pressure operation.

Fig. 3 is a longitudinal section showing a preferred form of atomizing cone. v

The sprayin device 1s preferably shaped like a pistol an the needle valve may be oper- When the device is constructed for relai tively high pressure operation the air is admitted into a nozzle chamber provided with an annular nozzle from which the air is ejected on to an impeller wheel driving the centrifugal cone. For relatively low pressure operation the air is preferably admitted throughthe piston butt formed as'a pipe from whence it passes through guide vanes to the impeller wheel.

The shaft of the centrifugal cone is mount- 4ed in a bearing member having conical guide surface for the air current. In order to avoid the entrance of, for example, paint in the bearing, the bearing member is bored in front to form a. cylindrical chamber round the shaft and apassage through the bearing member communicates with the rear end of this chamber. Thus any liquid which-may tend to creep up the4 shaft is blown out by a current of air.

Referring now to Fig. 1, in a cylindrical guiding and bearing member 8 with conical guide surfaces. This member forms the bearmg for a rotating shaft 14 which is driven by an impeller wheel 15 acting as a rotor.

The impeller wheel sets into rapid rotation a centrifugal conical plate 17 provided with steps.

The liquid to be sprayed, paint, colour and 'the-like, 1s conducted to the atomizing device by means of a valve 18 employing a regulating needle 19 though an inflow pipe 20 and is thrown out on all sides bythe atmizer in centrifugal direction. The impeller 15 is driven by compressed air which flows out of the annular gap of a nozzle member21- and is admitted' through a4 tube 22 which can be closed. This com ressed air flows through the pistol in thedirection ofits axis and is guided by means of a nozzle cap 16, which is adjustable in an axial direction so that the liquid mist centrifuged by the atomizing device is diverted and projected forward in the direction of the axis of the pistol, said nozzle cap having its front edge or end converging forwardly in the shape of a short truncated cone.

The needle 19 of the liquid valve 18 is operated by a trigger 23 chiefly by means of a double lever 26-27 in two parts and a drawrod 31. The double lever 26-27 turns about a pivot 29 mounted on a projection on the casing and isvunited from the two singlearmed levers 26 and 27 by a projecting pin 28 which can be removed. If the pin is drawn out the single-armed lever 27, which holds the valve needle 19 by pins with a forked slot, can be turned in the direction of the arrow 34 and the valve needle with all loose parts belonging to the liquid valve 18 can be removed in the direction of the arrow 33 for the purpose of cleaning. In order at the same time to keep together all parts which can be taken loose, such as stuling box and follower nut, a shortl `projecting pin 37 is passed through the valve needle.

The draw-rod 31 bears on its upper end a block or bracket 25 provided with bearing pins for the one-armed lever 26 and with an adjustable set screw 24 for regulating the stroke of the valve.

The force for closing the valve is` provided by acompression spring in a guide sleeve 30. This sleeve is mounted on the casing 40 on which the hand grip or pistol butt 32 is secured. In order to prevent paint or Y other liquid from entering the bearings, the bearing member 8 is provided with a passage 35 which terminates in a cylindrical chamber 36, round the shaft 14 through which the air ilows.

In Fig. 2 which shows a modication suitable for the low pressure, the compressed air flows into the pistol through a pistol grip 12 formed as a wide pipe. As rear pressure bearing for the shaft 14 of the impeller l54 out at 45 as shown. 'At some distance be-V hind the conical body a funnel-shaped rear wall 41 is secured on the cone by means of spacing bolts 42. The liquid to be sprayed flows to the interior of the so formed atomizing l device fromthe valve, not shown, through a small tube 43. When centrifugal force is applied, the liquid is rapidly whirled in radial direction between the rear side of the cone and the rear wall 41 and so atomized. The base of the cone slopes backwards as at 46 from the outer edge to the edge of the recess. The iine particles of mist are diverted towards the front by the bent-over edge 44 of the rear wall and projected towards the surface of application. The particles of liquid reaching the front of the centrifugal cone are then engaged by the envelopingcurrent of air from the nozzle and thus further atomized and projected forward.

I claim:

1. A liquid spraying device of the air brush type comprising a closed hollow body, having an air exit at its front end, means for admitting air under pressure to said body, a rotary mechanical atomizer at the front end of said body adjacent said air exit, means for projecting material to be sprayed onto said rotary atomizer, and a rotor within said body and driven by the compressed air therein and having driving connection to said rotary atomizer.

2. A liquid spraying device of the class .described comprising a substantially cylindrical closed body having an annular air exit i ii its front end adapted to supply a jet of air in thev shape of a closed cone, a mechanical atomizer mounted at the front end of said body on a rotatable shaft arranged longitudinally of said body, an impact rotor located within said body and operatively connected by means of. said shaft to said mechanical atomizer, means for admitting air under pressure to said bod in rear of said impeller, and means for feeding the liquid to be sprayed to said mechanical atomizer. y

3. A liquid spraying device of the class described comprising a substantially cylindrical t body, a bearing member mounted in the front end thereof, there being an annular air exit past said bearing member, a spindle rotatably mounted in said bearing member, a mechanical atomizer carried by the frontend of said spindle of less diameter than said annular air eiu't, an impact rotor located within said cylindrical body carried by the rear end of said spindle, means for admitting air to said body in rear" of said impeller, and means for feeding liquid to be sprayed into juxtaposition to said atomizer.

4. A liquid spraying device of the class described coniprising a substantially cylindrical body, a bearing member mounted in the front end thereof, there being an annular air exit past said bearing member, a spindle rotataly mounted in said bearing member, a mechanical atomizer carried by the front end l of said spindle `of less diameter than said annular air exit, an impact rotor located Within said annular body and carried by the rear endof said spindle, a lmember within said body having an arf-nular ai; passage, means for supplying air under pres-sure to said member, and means for feeding the liquid to be sprayed to said atomizer.

5. A liquid spraying device ofthe class described comprising a substantially cylin-` drical body, a sleeve member adjustable on the front end of said body and having a forwardly converging front end, a bearing member within the front end of said body spacedv -operated by said air for rotating said atomtherefrom, said bearingA member having an inclined wall opposed to the inclined portion of the sleeve and forming therewith air exit means converging towards a prolongation of' the axis of the cylinder, a cone shaped mechanical atomizer rotatably carried by said bearing member, lmeans for feeding liquid to the base of said cone, means for admitting air under pressure to said body, and means lzer. l

6. Apparatus according to claim 5 in which the atomizer is in the form of a stepped cone.

. the front, a spindle rotatably mounted in L said bore, an air passage leading from the interior of the casing through said block to 7. A liquid spraying device of the class described'comprising a casing having` a bear.- ingblock in its front end and an annular air exit in said end, said block having Aan axial bore with an annular enlargement towards i the annulars space formed by said enlargement, a rotary mechanical atomizer mounted on said spindle within the space defined by a prolongation of the annular air exit,- a rotor adapted to be operated by compressed air carried by the' rear end of said spindle, means' for-admitting air under Apressure to said casing, and means for .feeding liquid to be sprayed to said atomizer.

8. -A liquid spraying device of the class described comprising a hollowbody having an air exit at the front end, a rotary mechanical atomizer at said end, means for admitting air under pressure to said body, a rotor in said body operated by said air and operatively connectedto said'atomizer, a fee'd tube for .supplying liquid toy said atomizer, a reexit adjacent said atomizer, a needle valve controlling the liquid feed, a pair of levers Y fulcrumed upon ,a common fixed pivot and having'overlapping parts, means for detachably loclngsaid levers together, means fordetachably connectingone of said`levers to the needle valve, and a tri r assoclated with said pistol handle and operatively connected to the other lever.

10.V A liquid spraying device of the air brush type comprising a closed hollow body having an annular forwardl converging air exit at its' front end, means or admitting air under pressure to said body, a. circular rotary mechanical atomizer at the front end of said belly having a substantially uninterrupted-periphery adjacent said annular au' exit, means or feedin material i besprayed to the rearvfacefof sai rotary atomizer within the peripheral edge thereof, and a. rotor within saidj body and driven by the compressed air therein and having driving connection with said rotary atomizer.

In testimony whereof I have hereunto affixed my signature.

movable needle valve for controlling the feed through said tube and means for operating said needle valve includingtwo levers fulcrumed to pivot about a common axis and having overlapping 'parts provided with transverse openings, and a connecting pin Y los . lll 

